contactors

[c.k.]

I have a question in relation to having more that one 40A shower on a 60 A supply. I'm not intending doing this myself, would just like to know how it is done.

Here's what I saw done before:
Two separate MCB's and a 20A contactor alongside them in the CU.

How is this contactor wired?

Why is it only 20A?

Is it possible to supply more than 2 showers using this method?

 

[Big_Spark]

I have a question in relation to having more that one 40A shower on a 60 A supply. I'm not intending doing this myself, would just like to know how it is done.

Here's what I saw done before:
Two separate MCB's and a 20A contactor alongside them in the CU.

How is this contactor wired?

Why is it only 20A?

Is it possible to supply more than 2 showers using this method?

Total cr*p, to power a single device in this way is potentially fatal if anything goes wrong, it is electrically one of the worst things I have heard suggested in 22 years and I would not give out any information of such a lash up.

 

[c.k.]

I have seen it done on two occasions, both by professional electricians.

Just out of curiosity, could you explain to me what was done here. What was wrong with it and the correct method of doing this? (setting wiring up two showers, so as both cannot be used together)

 

[Big_Spark]

I have seen it done on two occasions, both by professional electricians.

Just out of curiosity, could you explain to me what was done here. What was wrong with it and the correct method of doing this? (setting wiring up two showers, so as both cannot be used together)

Now what your saying is completely different from what your first post says.

What you are saying is installing TWO seperate showers into the building, each with an interlocked supply so only one can be used at a time.

That is easy to do, however..whats the blooming point of going to all that expense of installing two showers and all the control gear when you can only use them one at a time!!

Lastly, putting a shower on a 60A supply is pushing the limit of the supply capabilities, this would need to be looked at carefully to ensure that the supply could not be accidently overloaded.

 

[altec]

I have a question in relation to having more that one 40A shower on a 60 A supply. I'm not intending doing this myself, would just like to know how it is done.

Here's what I saw done before:
Two separate MCB's and a 20A contactor alongside them in the CU.

How is this contactor wired?

Why is it only 20A?

Is it possible to supply more than 2 showers using this method?

I think the question is the same. But you haven't really answered it. What did you think i was talking about

 

[c.k.]

why has my name appeared as 'altec'

 

[breezer]

why has my name appeared as 'altec'

becasue you loged off and back in again with differnt details?

 

[Big_Spark]

I have a question in relation to having more that one 40A shower on a 60 A supply. I'm not intending doing this myself, would just like to know how it is done.

Glad to hear that your not planning to do this

Here's what I saw done before:
Two separate MCB's and a 20A contactor alongside them in the CU.

How is this contactor wired?

This is certainly implying that two contactors are controlling one shower via either a single or dual contactors, depending on how you read it.

This is very dangerous and the type of **** that causes death, injury and fire.

Why is it only 20A?

Whether it is two 20A contactors or one 20A contactor is irrelevent, this is dangerous.

Is it possible to supply more than 2 showers using this method?

I have answered this question in my second post in this thread.

 

[c.k.]

I'm none the wiser now than I was in the beginning, I'll try and ask my question again, as clearly as possible.

I have two 40A showers in my house, which i do not want to run together. So i get two 40A MCB's and a 20A contactor. Correct?

1. How is this setup wired

2. Why is only a 20A contactor used (why not 40A, you see, i dont really understand how this work's, what it is switching)

3. Is it possible to have more than two showers set up like this (i.e. have three showers in my house with only one working at once)

 

[securespark]

Oh, dear.

 

[Big_Spark]

I'm none the wiser now than I was in the beginning, I'll try and ask my question again, as clearly as possible.

I have two 40A showers in my house, which i do not want to run together. So i get two 40A MCB's and a 20A contactor. Correct?

1. How is this setup wired

2. Why is only a 20A contactor used (why not 40A, you see, i dont really understand how this work's, what it is switching)

3. Is it possible to have more than two showers set up like this (i.e. have three showers in my house with only one working at once)

I have said it before and I will say it again...NO you cannot do this in your installation.

Why would you want three showers that can only be used one at a time?? It does not make sense, common, economic or electrical.

 

[c.k.]

ELECTRIC SHOWERS

RECI Contractors have been enquiringabout the installation of two 9 Kw showersin domestic premises.

If two 9 Kw showers are on at the same time they draw quite a high current, in or around 80 amps depending on the voltage. In many cases to provide this load in a domestic installation would require an additional supply from the ESB. Most domestic installations are fedthrough a 63 amp consumers fuse.

If however it can be arranged that both showers cannot be on together the shower load on the system is limited to around 40 amps. Some contractors have been feeding both showers from one 40 amp MCB allowing the MCB to trip when the overload exceeds the tripping curve. This is not the solution.

Apart from the nuisance of both showers tripping, MCBs are not designed for this purpose. They are designed as protective devices to operate occasionally and certainly not to switch twice full load on a regular basis.

Such a method would be deemed to be bad design, a more suitable alternative scheme would be to use two 40 amp contactors wired so that only one is closed at any time in a kind of leader/slave arrangement - one contactor/shower being the primary shower.

Or probably the best solution would be the installation of a 40 amp 4 pole contactor changeover or remote switch with 2 normally open and 2 normally closed contacts. This would prevent both showers being in operation at the same time.

This is from irelands RECI website.

You see, i have ensuite bathrooms, please stop trying to tell me that this is not needed. I'm beginning to come to the conclution that you don't know what your talking about. My questions again:

How is this setup wired (above)

Why is only a 20A contactor used (why not 40A, you see, i dont really understand how this work's, what it is switching)

Is it possible to have more than two showers set up like this (i.e. have three showers in my house with only one working at once)

 

[Big_Spark]

CK, please re-read the article you have posted, it clearly states 40A as the contactor rating.

Ireland is not the UK for starters regarding electrical regs, however if this were done properly then it could be done in the UK, I agree, HOWEVER please explain the practical point to me?

If your porperty is so small that it only has a 60A head, why do you want to install 2 showers in such a way only one can be used at any one time..

It would make sense to have people use one shower, and when they finish the nextn person uses it.

Regarding being rude, it is uneccessary, I do know what I am talking about, unlike you, so if you don't like what your hearing, please go to B&Q and take advice from them rather than staying here and insulting people.

 

[ban-all-sheds]

Unlike FWL, I can see why you would want this, if you've got en-suite bathrooms, but it really is a kludge to get round the problem of not having enough power for your house, and fixing that is the way to go.

Why is only a 20A contactor used (why not 40A, you see, i dont really understand how this work's, what it is switching)

FWL has already pointed out the discrepancy between your repeated assertion that a 20A contactor is used, and the article you quoted which clearly states it is 40A. If you don't understand how a changeover relay or contactor, or a BBM switch controlling multiple relays or contactors can be used to switch circuits on and off, then this is probably not the level at which you should be entering the field of DIY wiring....

 

[c.k.]

I know that this article states 40A but i have seen 20A used on two occasions before, is this simply an underrated contactor?

Could we leave the practical issues of why one would want to do such a thing and just state whether it is technically possible to:

have more than 2 showers wired up in this way (e.g 3 or 4)

Ban, please bear in mind that as already stated, i am asking this question purely in a theoretical capacity. I have a 100A supply myself but this is irrelevant.

Also is a wiring available which would simply explain how this is done (just out of interest)